For centuries, concrete has been a go-to building material for everything from residential foundations to parking garages. However, concrete has always had the problem of cracking associated with it. A beautiful driveway or patio can easily be marred by a huge crack developing through its center. Worse, a building foundation with cracked concrete can compromise the integrity of the entire structure and allow moisture to enter the building. At least that’s the way things used to be. Today, self-healing concrete can give home and business owners the sleek, professional look of concrete without having to worry about cracking and costly repairs.
What is self-healing concrete?
Self healing concrete, also known as self mending concrete or bio concrete, uses a variety of new technologies to create a building product that will actually mend any cracks that appear in the concrete due to wear, changing temperature, shifting ground or other occurrences. This not only makes the concrete more attractive, but also more durable.
Making concrete more durable also makes it more environmentally friendly, since it won’t have to be disposed of and replaced nearly so often, nor will it have to be repaired using extra concrete. According to Nima Rahbar, an associate professor of civil and environmental engineering at Worcester Polytechnic Institute, concrete production is responsible for as much as nine percent of the world’s carbon dioxide emissions. In fact, if concrete producers were a country, it would be the third-largest climate polluter in the world.
How self-healing concrete works
One of the most exciting new building products on the market, this new type of concrete can be made using a variety of processes. One uses an enzyme found in human red blood cells to “heal” the concrete. Another, developed by a researcher at Delft University of Technology in the Netherlands, uses bacteria. Some types of bacteria can thrive in arid, harsh environments, such as found in and around concrete. The bacteria used can produce spores that can live up to four years without any food or oxygen. The researcher used bacteria that would produce limestone, which kept the bacteria alive and provided material to repair the cracked concrete.
Another method of producing self healing concrete, developed by an engineering student at the University of Rhode Island, uses a microencapsulated sodium silicate healing agent that ruptures as the crack forms and acts to repair the crack
Examples of self healing concrete
Self healing concrete is already being tested in the real world. One example was spearheaded by three universities in the UK. They used a concrete mixture with microcapsules of sodium silicate to build mock retaining walls and highway sections in South Wales, UK. The project was a test, and one section used traditional concrete while the other used the concrete mixture. The test was a success, with all the self-healing concrete panels exceeding the performance of those made using traditional concrete construction materials.
The future of self-healing concrete
Self-healing concrete changes how we look at using concrete for buildings and surfaces. It can totally eliminate invasive building maintenance and expensive repairs and replacements to foundations, driveways, sidewalks and patios.
Most types of self mending concrete are much more expensive to produce than traditional concrete. While you can argue that the ultimate price of this building material is less, for contractors trying to compete on price, this can be a disadvantage. The self healing concrete price right now is about double that of traditional concrete.
This new type of concrete mix is still in the development stages, and it remains to be seen which formula will become the most commercially viable. However, look for this exciting product to be a game-changer in the construction industry in the next few years.